Reciprocatable-plunger type control valve

ABSTRACT

A control valve comprises a valve assembly disposed within a housing and including a valve member movable to open and closed positions with respect to a passageway between the housing inlet and outlet. The valve assembly further includes a plunger reciprocatable within a chamber to an extended position causing the valve member to close the passageway, or to a retracted position permitting the valve member to open the passageway. The control valve further includes a presettable limit member presettable within the chamber to be engaged by the plunger to fix its retracted position, and thereby to preset the magnitude of reciprocatory movement of the plunger and the cross-sectional area of the passageway when the valve member is in its open position.

BACKGROUND OF THE INVENTION

The present invention relates to a control valve for controlling theflow of a fluid. The invention is particularly applicable tosolenoid-actuated control valves of the diaphragm type, and is thereforedescribed below with respect to such valves, but it will be appreciatedthat the invention could advantageously be used in other types ofcontrol valves as well.

Many types of control valves are known including a valve member (e.g., adiaghragm in a diaphragm-valve) which is movable to open and closedpositions with respect to a passageway between an inlet port and anoutlet port of the valve. One type includes a plunger reciprocatablewithin a chamber to an extended position causing the valve member(diaphragm) to close the passageway, or to a retracted positionpermitting the valve member to open the passageway. Such valves,however, are not entirely satisfactory for a number of applications. Forexample, in applications requiring relatively high-frequency operation(e.g., in the order of 15-80 actuations per second), such high-speedoperation is usually not attainable with the known diaphragm valves ofthis type because of the magnitude of the plunger reciprocatory movementrequired during each valve operation. Another disadvantage of the knowndiaphragm valves of this type is that the fluid flow through the valvein its open condition is usually prefixed by the smallestcross-sectional area in the fluid path when the valve member is in itsopen position, which means that many different valve sizes are requiredfor different applications involving different flow rates, therebyincreasing the manufacturing costs and the inventory requirements forsuch valves.

An object of the present invention is to provide a control valve havingadvantages in the above respects.

According to a broad aspect of the present invention, there is provideda control valve for controlling the flow of a fluid, comprising ahousing having an inlet port, an outlet port, and a passagewaytherebetween; and a valve assembly disposed within the housing andincluding a valve member movable to open and closed positions withrespect to the passageway. The valve assembly further includes a plungerreciprocatable within the housing to an extended position wherein oneend of the plunger engages the diaphragm causing the diaphragm to closethe passageway, or to a retracted position permitting the diaphragm toopen the passageway. The control valve further includes a coiled springenclosing the plunger and having one end secured to the plunger, and theopposite end secured to the housing for urging the plunger to one of thepositions; and an actuator for actuating the plunger to the other ofsaid positions; and a presettable limit member presettable within thechamber to be engaged by the end of the plunger opposite to thatengageable with the valve member to fix the retracted position of theplunger, and thereby to preset the magnitude of reciprocatory movementof the plunger and the cross-sectional area of the passageway when theplunger is in its open position.

As indicated above, the invention is particularly useful with respect todiaphragm-type control valves, wherein the valve member is a diaghragm.

Control valves, particularly of the diaphragm type, constructed inaccordance with the above features provide a number of importantadvantages over the presently known diaphragm-type control valves: Oneimportant advantage is that by presetting the limit member, themagnitude of the reciprocatory movement of the plunger can be pre-fixed,e.g., shortened in order to increase the speed of operation of thecontrol valve; thus, diaphragm-type control valves of known constructionoperating at a maximum speed of 12 operations per second have beenmodified in accordance with the foregoing features to increase theirspeed to about 80 operations per second. Another advantage in theforegoing construction is that by presetting the position of the limitmember, the position of the plunger in its retracted condition can bepreset to fix the cross-sectional area of the passageway between theinlet and outlet ports; thus, control valves may be supplied accordingto a standard construction and then adjusted, by presetting the limitmember, to adapt it to the various applications requiring different flowrates.

Further features and advantages of the invention will be apparent fromthe description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings, wherein:

FIG. 1 is a side-elevational view illustrating one form of control valveconstructed in accordance with the present invention;

FIG. 2 is a longitudinal sectional view of the control valve of FIG. 1;and

FIG. 3 is an exploded view illustrating the parts in the control valveof FIGS. 1 and 2.

DESCRIPTION OF A PREFERRED EMBODIMENT

The control valve illustrated in the drawings is of thesolenoid-actuated type including a diaphragm valve member. The latter isdisposed within a housing, generally designated 2, to be connected to asource of pressurized fluid, e.g. air, via an inlet fitting 4 forcontrolling the outlet of the fluid to a distributor 6 which distributesthe fluid to a plurality of output tubes 8. One application of such acontrol valve is for controlling the operation of a punching machinewherein, during the operation the machine, pressurized-air pulses areapplied via the outlet tubes 8 to various parts of the machine under thecontrol of the solenoid 10 which actuates the control valve supplyingthe air pulses to the distributor 8. The present invention is primarilyconcerned with the structure of the control valve and the manner ofactuating it by the solenoid 10, and therefore the remainder of thedescription will be restricted to this portion of the illustrateddevice.

Housing 2 is made of a solid block of metal formed with a bore 12passing partly through it and enlarged at its inner end 14 for thereception of a diaphragm 16. Housing wall 18, opposite to that havingthe bore 12, is formed with another bore 20 serving as the inlet port tobe connected to the inlet fitting 4, and a further bore 22 serving asthe outlet port to be connected to the distributor 6. The middle portionof diaphragm 16 is displaceable, as will be described below, either awayfrom wall 18 to open a passageway between the inlet port 20 and theoutlet port 22, or firmly against wall 18 to close this passageway.

The control valve further includes a plunger 30 reciprocatable within achamber 32 defined by bore 12 and a tubular plunger housing 34 securedto housing 2 in communication with bore 12. Plunger 30 is movable withinchamber 32 either to an extended position, in firm engagement withdiaphragm 16 thereby causing it to close the passageway between the twobores 20 and 22, or to a retracted position away from the diaphragmthereby permitting it to open this passageway between the inlet andoutlet bores. Plunger housing 34 is secured by threads 36 (FIG. 2)formed at its end receivable within the threaded end of bore 12, and anut 38 fixed to the plunger housing to facilitate its rotation whenattaching it to the main housing 2.

Plunger 30 is biased to its extended position causing diaphragm 16 toclose the passageway between the inlet and outlet ports 20, 22, by meansof a coil spring 40 having one end fixed to plunger 30 and the oppositeend fixed to its housing 34. Solenoid 10 encloses plunger 30 such thatwhen the solenoid is actuated, the plunger is moved to its retractedposition, thereby permitting diaphragm 16 to be displaced, by thepressurized air applied to inlet port 20, to open the passage for theflow of the air to the outlet port 22.

Solenoid 10 is formed with a bore 42 (FIG. 3) receiving the plungerhousing 34 and is secured thereto by a nut 44 threaded onto the threadedend 46 of the plunger housing. The solenoid is provided with a pluralityof terminals 48 projecting through a cover plate 50 for connection tothe electrical conductors 52 actuating the solenoid, which electricalconductors pass through a fitting 54 secured to the solenoid.

The outer end of plunger housing 34 is also formed with internal threads56 receiving an enlarged, externally-threaded portion 58 of a rod 60passed through the plunger housing 34. The inner end of rod 60 isdisposed within chamber 32 so as to be engageable by the end of theplunger 30. The outer end of rod 60 extends externally of the plungerhousing 34 and is attached to an external handle 64 by means of a screw66, the latter being covered by a removable cover plate 68. The externalend of rod 60 secured to handle 64 is formed with a rib or key 70,received within a complementary socket in the handle 64 such thatrotation of the handle will also rotate rod 60.

Rod 60 is further formed with a threaded portion 72 adapted to receive alocking nut 74. A pair of sealing rings 76, 78 are received in annularrecesses 76', 78', respectively, in the inner end of the rod to sealchamber 32 from the atmosphere. In diaphragm control valves of theforegoing type, the diaphragm 16 is usually provided with one or moresmall openings therethrough so as to equalize the pressure on theopposite sides of the diaphragm. Accordingly, the sealing rings 76, 78assure that in such valves, the pressure within the valve housing 2 willnot escape to the atmosphere through the plunger housing 34.

The inner end of rod 60 carries a limit member or disc 80 engageablewith plunger 30 for limiting the magnitude of its movements during itsreciprocations within chamber 32. Plunger 30 is of metal, and to avoid ametal-to-metal contact, limit disc 80 is preferably of hard plasticmaterial. It is removably attached to the end of rod 60 by means of aconical stem 82 frictionally fitted into a complementary socket formedin the end of the rod.

The illustrated control valve may be used in the following manner:

First, the valve is assembled by inserting diaphragm 16 into the annularrecess 14 of housing 2; attaching plunger housing 34, with the plunger30 within it, to valve housing 2 by threading end 36 of plunger housingwithin the threaded end of bore 12; passing the solenoid 10 throughplunger housing 34 and attaching the solenoid housing thereto by meansof nut 44 applied to threads 46; and then attaching the handle 64 to thekeyed end 70 of rod 60. When the control valve is so assembled, it willbe seen that the limit disc 80 at the inner end of rod 60 is disposedwithin chamber 32 in alignment with the outer end of plunger 30. Theposition of this limit disc 80 may be adjusted towards or away fromplunger 40 by rotating handle 64, this causing threaded section 58 ofthe rod to move in threads 56 of the plunger housing 34. When the limitdisc 80 has been located at the desired preselected position in chamber32, rod 60 may be locked in this position by threading nut 74 alongthreads 72 until it engages nut 44 locking the solenoid 10 to theplunger housing 34.

It will thus be seen that the reciprocatory stroke of the plunger can beconveniently preset either for purposes of increasing the speed ofoperation of the control valve by reducing the magnitude of the plungerstroke, and/or for purposes of changing the cross-sectional area of thepassageway between the inlet and outlet ports, this passageway beingdefined by the diaphragm in the retracted position of the plunger.

It will be appreciated that many variations and modifications of theabove-described embodiment could be made. For example, the displaceablevalve member, instead of being a diaphragm, could be a piston moving ina cylinder. In addition, instead of using a solenoid actuator, therecould be used a hydraulic or pneumatic-type actuator.

Many other variations, modifications, and applications of the inventionwill be apparent.

What is claimed is:
 1. A control valve for controlling the flow of afluid, comprising: a housing having an inlet port, an outlet port, and apassageway therebetween; and a valve assembly disposed within saidhousing and including a valve member movable to open and closedpositions with respect to said passageway; said valve assembly furtherincluding a plunger reciprocatable within said housing to an extendedposition wherein one end of the plunger engages said valve membercausing said valve member to close said passageway, or to a retractedposition permitting said valve member to open said passageway; a coiledspring enclosing said plunger, and having one end secured to saidplunger and the opposite end secured to said housing for urging saidplunger to one of said positions; and actuator for actuating saidplunger to the other of said positions; and a presettable plastic limitmember presettable within said housing to be engaged by the end of theplunger opposite to that engageable with the valve member to fix theretracted position of the plunger, and thereby to preset the magnitudeof reciprocatory movement of the plunger and the cross-section area ofsaid passageway when the valve member is in its open position.
 2. Thecontrol valve, according to claim 1, wherein said valve member is adiaphragm.
 3. The control valve according to claim 1, wherein saidpresettable plastic limit member is carried at the end of a rodthreadedly received in said housing to preset the limit member by movingsame towards or away from said plunger, said rod including a sealingring between its outer surface and said housing.
 4. The control valveaccording to claim 3, wherein said plastic limit member is in the formof a plastic disc removably attachable to the inner end of said rod. 5.The control valve according to claim 3,wherein the outer end of said rodcarries a rotatable handle externally of said housing, which handle maybe rotated to preset the position of said limit member with respect tosaid plunger.
 6. The control valve according to claim 3,wherein said rodfurther includes a locking nut for locking said rod in its presetposition.
 7. The control valve according to claim 1, wherein said coiledspring encloses said one end of the plunger.
 8. The control valveaccording to claim 1, wherein said spring biases said plunger to itsextended position engaging said valve member, and said actuator actuatesthe plunger to its retracted position away from said valve member. 9.The control valve according to claim 8, wherein said actuator is asolenoid.
 10. A control valve according to claim 1,wherein said inletport and outlet port are formed in a common wall in said housing, saidvalve member being movable away from said common wall to open saidpassageway, or against said common wall to close said passageway.
 11. Acontrol valve for controlling the flow of a fluid, comprising: a housinghaving an inlet port, an outlet port, and a passageway therebetween; anda valve assembly disposed within said housing and including a diaphragmmovable to open and closed positions with respect to said passageway;said valve assembly further including a plunger reciprocatable withinsaid housing to an extended position wherein one end of the plungerengages said diaphragm causing said diaphragm to close said passageway,or to a retracted position permitting said diaphragm to open saidpassageway; said control valve further including a coiled springenclosing said plunger and having one end secured to said plunger, andthe opposite end secured to said housing for urging said plunger to oneof said positions; an actuator for actuating said plunger to the outerof said positions; and a presettable plastic limit member memberpresettable within said chamber to be engaged by the end of the plungeropposite to that engageable with the valve member to fix the retractedposition of the plunger, and thereby to preset the magnitude ofreciprocatory movement of the plunger and the cross-sectional area ofsaid passageway when the diaphragm is in its open position.
 12. Thecontrol valve according to claim 11, wherein said presettable plasticlimit member is carried out at the end of a rod threadedly received insaid housing to preset the limit member by moving same towards or awayfrom said plunger, said rod including a sealing ring between its outersurface and said housing.
 13. The control valve according to claim 12,wherein said plastic limit member is in the form of a plastic discremovably attachable to the inner end of said rod.
 14. The control valveaccording to claim 12, wherein the outer end of said rod carries arotatable handle externally of said housing, which handle may be rotatedto preset the position of said limit member with respect to saidplunger.
 15. The control valve according to claim 12, wherein saidcoiled spring encloses said one end of the plunger.
 16. A control valvefor controlling the flow of a fluid, comprising: a housing having aninlet port, an outlet port, and a passageway therebetween; and a valveassembly disposed within said housing and including a valve membermovable to open and closed positions with respect to said passageway;said valve assembly further including a plunger reciprocatable withinsaid housing to an extended position wherein one end of the plungerengages said valve member causing said valve member to close saidpassageway, or to a retracted position permitting said valve member toopen said passageway; said control valve further including a coiledspring enclosing said plunger, and having one end secured to saidplunger and the opposite end secured to said housing for urging saidplunger to one of said positions; an actuator for actuating said plungerto the other of said positions; and a presettable plastic limit memberpresettable within said housing to be engaged by the end of the plungeropposite to that engageable with the valve member to fix the retractedposition of the plunger and thereby to preset the magnitude ofreciprocatory movement of the plunger and the cross-sectional area ofsaid passageway when the valve member is in its open position; saidpresettable plastic limit member being carried at the end of a rodthreadedly received in said housing to preset the limit member by movingsame towards or away from said plunger, said rod including a sealingring between its outer surface and said housing.
 17. The control valve,according to claim 16, wherein said valve member is a diaphragm.
 18. Thecontrol valve according to claim 16, wherein said plastic limit memberis in the form of a plastic disc removably attachable to the inner endof said rod.
 19. The control valve according to claim 16, wherein saidcoiled spring encloses said one end of the plunger.
 20. The controlvalve according to claim 16, wherein said actuator is a solenoid.